China sent out Wednesday what may be perhaps the most future-oriented messages in years toward Japan as it held a memorial ceremony for victims of the 1937 massacre committed by Japanese troops in Nanjing, with President Xi Jinping attending for the first time in three years.

Amid growing signs that efforts by the two countries to improve relations are picking up pace, Xi gave no speech at this year's state commemoration, which marked the 80th anniversary of the tragedy in the eastern Chinese city.

Instead, Yu Zhengsheng, chairman of the National Committee of the Chinese People's Political Consultative Conference, delivered an address, aired live by the country's official broadcaster, in which he started by saying, "The inhumane crime of the Japanese invaders was outrageous and left a very dark page in human history."

While Xi took a low-profile, Yu said, "The Chinese people and people of all countries in the world will never forget. Only by correctly understanding history can we build a better future."

Still, he later spoke at some length about the future of Sino-Japanese relations, pointing out that the two countries are "neighbors that cannot move away" with a long history of civil exchanges.

Noting also that this year marks the 45th anniversary of the normalization of diplomatic ties between the two countries, he said the focus should be on expanding the basic interests of their citizens.

"China and Japan should accurately grasp the general direction of peace, friendship and cooperation, draw lessons from history, look forward to the future...and jointly contribute to the peace of mankind," said Yu, who retired as one of the seven members of the Communist Party's elite Politburo Standing Committee in October.

The memorial service came a month after Xi agreed with Japanese Prime Minister Shinzo Abe that "positive" developments are increasing and they should push forward the momentum of a "new start" in the bilateral relationship.

In Tokyo, Japan's top government spokesman Yoshihide Suga said he wants to "take note" of Yu's reference in his address to the 45th anniversary and next year's 40th anniversary of the two countries' treaty of friendship and peace.

"It is extremely important to show that we will make future-oriented efforts, while valuing the current trend of improving Japan-China relations," Suga told a regular press conference.

But Xi's appearance at the annual observance signals the Communist Party-led government's strong determination to remember the Imperial Japanese Army's atrocities, which also included raping and looting, and not to compromise on its version of wartime history.

On the other hand, by not making a speech, Xi avoided any possibility of setting back the rapprochement of recent months between the two countries.

The scale of Japanese troops' killing of civilians and soldiers while capturing Nanjing, then the capital of the Nationalist Chinese government of Chiang Kai-shek, and during the several weeks that followed has been the subject of much debate.

China claims the Japanese army slew more than 300,000 people in the city, formerly spelled as Nanking, while Japanese historians' estimates of the death toll of Chinese civilians and soldiers vary from tens of thousands to 200,000.

Xi first delivered a speech at the Memorial Hall of the Victims in Nanjing Massacre by Japanese Invaders in 2014, when China designated Dec. 13 as a "national" memorial day.

Since then, however, no one from the Politburo Standing Committee, the apex of Chinese politics, had appeared for the ceremonies, which have been joined by survivors, government officials, soldiers and students.

The Communists hardly spoke of the military rampage before the early 1980s as it took place in the area controlled by the Nationalist forces, their enemy in China's civil war.

Now though, not just the massacre during the Sino-Japanese War that preceded World War II, but the Imperial Japanese Army's actions as a whole are often highlighted by the Communist Party.

The approach has helped the party reinforce its legitimacy, a linchpin of which rests on the assertion that it played the central role in defeating Japanese militarism.

China's frequent emphasis on Japan's war guilt -- which has fostered nationalism among its citizens -- and some Japanese political leaders' unapologetic views on the country's militaristic past have complicated bilateral relations for a long time.